package ds.tree;

public class LevelOrderTraversal {
	
	private static class TreeNode{
		int value;
		TreeNode left = null;
		TreeNode right = null;
		
		TreeNode(int val){
			this.value = val;
		}
		
		public String toString(){
			return String.valueOf(value);
		}
	}
	
	private int height(TreeNode node){
		if(node == null){
			return 0;
		}
		return Math.max(height(node.left) +1, height(node.right)+1);
	}

	private void printLevelOrder(TreeNode d){
		int height = height(d);
		
		for (int i = 1; i <= height; i++) {
			printGivenLevel(d,i);
		}
	}
	
	private void printGivenLevel(TreeNode node , int level){
		if(node == null){
			return;			
		}
		if(level ==	1 ){
			System.out.print(node + " ");
		}
		printGivenLevel(node.left,level-1);
		printGivenLevel(node.right,level -1);
	}
	
	public static void main(String[] args) {
		LevelOrderTraversal lvlTraversal = new LevelOrderTraversal();
		lvlTraversal.printLevelOrder(tree());
	}
	private static TreeNode tree(){
		TreeNode A = new TreeNode(1);
		TreeNode B = new TreeNode(2);
		TreeNode C = new TreeNode(3);
		TreeNode D = new TreeNode(4);
		TreeNode E = new TreeNode(5);
		TreeNode F = new TreeNode(6);
		TreeNode G = new TreeNode(7);
		
		A.left = B;
		A.right = C;
		B.left = D;
		B.right = E;
		C.left = F;
		C.right = G;
		
		return A;
	}
}
